Telephone system



Feb. 24, 1931.

w. H. EDWARDS TELEPHONE SYSTEM File d Dec.

' lNVENTOR BY WEEdwarzis ATTORNEY Patented Feb. 1931 1 WILLIAM H.EnwARn's, or 'BnYsInE', NEW yonnn'ssrenon T AMERICAN 'rn'rurrrounnnnrnrnennrrr comranxtnconronierro v ornE'wYonK 'rnLErnoNnsY STE i V, d

\ Application filed member 21, .1938, {serial No. e27 ,'5o2l;,

This invention relatestote'lephone meter- .ing systems and moreparticularly to 'meth- 'ods and apparatus for gradually reversing thedirection ofcurr'ent flow in a telephone; system at predeterminedintervals of time v to operate ameter which records the length oftimethe telephone is in use. 5

It is an object of this invention to provide for periodically varying orreversing the di rection of Current flowin .a telephone sub scribersline to operate a timing meter lo cated at his substation withoutinterrupting the conversation or creating disturbances in the talkingcircu1t.- Y V The apparatus constituting-za part oftheinventioncomprises in 'combinationfa meter located at the subscribersstationadapted to r be operated'by current reversals' in the line towhich the battery is connected, a direct current generator equipped withbrushes which may be periodically shifted .toreduc e the currentproduced by the generator grad ually to 'zero and build it up againg-radually in the opposite direction, and means for periodically andsuccessively connecting, said generator in the circuit in parallel withthe 1 line battery, clisconnectingsaid line battery,

reversing the" output current of said' enero V ator by shifting ltsbrushes, reconnecting the loops extending to i As shown, Arepresentsthestation of the calling subscriber and 'B that of the called subscriber.There, are located at the stations meters and M which are adaptedtorespondto curi-entreversrls in the subscribers loops." V

The cord circuit C of the central oflice is here illustrated as theimpedance coil feed 7 type. Obviously, accord circuit ofthe're peatingcoil feed type may be lused, if de sired. The cord circuitshowncomprises the usual current source 3 grounded at'4,'a-cur noveliand efficient method of =andi-means rent-I supply fbridge comprisingthe capacitieslfi {and G'gth cord conductors- 7, 7/; Sand 8?. Land the?isupervisoly relay ,9; Normally,

grounded at 15, through the armatures- 10 and, 10, theconta'ctsl6- and-'16-' and the leads 17 and 17. i This switching means wliichis underthe control-of relay 9 comprises a relayv 18 grounded-fat 19,: thcontact 21,1the armature. 22 a and the source l, .Inv addition there islocated at the central ofiice a direct current generatorG ofs'ulostan-itially thesame voltage as; the source lt' whicfh- :comprises almagnetwith north pole'N-fand *south poles, the'armature25, th'ecommutator;

26 and thebrushes:27 and"28. -:Thearmature. l 25 isshown as the'closed'coil ringtypeand, includes a plurality of'coils"29aformingia 7closed circuit with leadsf3O-"connecting said the currentr supply bridge{of the calling subscriber is connected I: ;to.,the source 3 through thearmatures 10 and p 10", th'econtac-ts ll -and 11 and the leads 1 2.

' A switching means 13 is provided- I to disconnect ,the currentsupplyjbridge of the A calling a subscriber trom the source 3' and -toconnect it to the auxiliary source 'li,

coilsto the barsiofthe commutator26. '-Other types ofa-rmatures may beused iifdesired Brush'es'2 7i'and 28 are positioned so as to be incontact withopposite sides of the commutator 26 and are fastenedpreferably byrocking 'brush rigging to thecollector rings 31 and 32,respectively. The collector-ring 32 is supported by the spider 33andthe'collector ring 31 is rigidly I V ring 32 by the insulated joints34. Station- Ifastened to the; collector ary brushes 35 and 36 arepositioned so as to j be in'contact with collector rings 31 an'd'32',respectively. The collector rings 3l an'd 32:- with the brushes 27 and28,-;respectively, are

adaptedto be rotated periodically throughza predetermined are, forexample, one-halt rev- 7 --'olut1on.t =As shown, the'armature rotates ina clock-Wise d rect onand the collector r1ngs and brushes inacounterclockwise direction. An armature of-Itlie stationary type With arotating magnet may be used, ifolesired. j Any suitable drivingmeansmayibe used to cause the rotationof the collector'rings and 5;" e;'conductor: 20, the

brushes and any suitable means may be provided to regulate the arc andtime ofrctation.

As diagrammatically shown, the driving means. comprises a continuouslyrevolvlng 'motor 37 connected by shaft 38 through a friction clutch 39tothe spider -33 and-the regulating'means comprises a :solenoid 4L0whlch 1S momentarily energized at predeter- 1 mined intervals of time bythe closure of its circuit which is controlle'd by the clock mech anism53.. The-solenoid has an-armature'4t1" which, in its normal position,engages one of the stop lugs 42 or 43 which are fastened at oppositepoints on the surface of the collector ring 31. The momentaryenergization of the solenoid 40 attracts its armature 4:1 andreleasesits'engagement with the stolpflugt2.

Immediately thereafter and before the collector ring hascompleted itsone-half revolution, for example, the solenoidis 'deenergized and itsarmatureuis restored to itsnorrnal position by means of the ribbonspring 4 k to "engage the other stop in 0 stop lug -1Sreleased'fromengagement with the armature 41, the collector ring whichis under constant tension, due to its connection with andregulatingmeans shown nor to a magnet I I having only two poles; A1condenser'element,

the continuously revolving motor 37 through the shaft 38 and thefriction clutch39,ro

tates, for example, one-half revolution-atsuo' stantially constantspeeduntil its other stop lug 43 engages the'armature 41; Obviously, thebrushes 27 and28 are rotated the same time as the collector rings 31.and32ailt is'to be understood that this'invention is -not limited to theparticular formstof driving means 7 45, preferably. ofithe electrolytictype, is con- "'nected: in parallellwith the generator circuit I throughthe stationary brushes 416 Land 47 to absorb theripples in thecommutator current and to prevent any noise that might belcaused bygenerator operation from getting into the 'talking circuit.

ply bridge of Y The generator G is associated with the supthecalling-subscriber in parallel with the auxiliary source 14 through'theleads 4:8 and 49, the contacts and a'rmatures of'the relay 50 and theleads Hand 17.. The auxiliary source 14 is likewise associated with saidsupply bridge throughthe contacts and armatures of relays "51 M152 andthe leads 17 and 17 These relays' as well as-thesolen-oid 40; are underthe control of'thecloch mechanism 53 which includes the interrupters 54,

- 55, 56 and 57 supported and operated by' the shaft 58. T he circuit ofeach relay includes an individual ground connection, winding,

lead and brush which is in'contact with its corresponding interrupterand a comlnon'lead I 59 and a source 60'grounded at 61. The clockmechanism is designed to rotate the interrupters at aiconstant speed,for example, onerevolution every thirty seconds during which time tworeversals ofthe line current, take respect to theneutral area of the (Yl3; As soon as the :lay 51. p is supplying current tothe callingsubscriber s carbon of high contact resistance and being made largeenough to be in contact wlth at leasttwo commutator bars at all timesare normally located in an advanced position,with 7 I magnetic field andthe direction of rotation. Also,'the self-induction of each coil on thearmature is reduced to a minimum. Thisis obtained with the givenZvoltage and current output 7 by employing a maximum number =oflc0ils,coinmensurate with practical design with a min- 1mnm number ofturn ineachcolln Llkewlse,

the I provision of.- comparatively *iwide' pole pieces, as shown,distributes the. magnetic vfield uniformly over a large" area? andavoids I y w H 2200 The operation of-the systemis as follows: Nhenthefcallingsubscriber at station Ali-removes flllS receiver from"thehook to: initiate 'a calh'the operator. in response to the signalconcentration at any one point.

establishes a connection-to thelcentral office in? the' well knownmanner. Atthis time, the current flows from theaposit'ive terminal ofthe source 3 through the lead 12, the contact-11, the armature 10, theupper left impedance coil 5, the cord conductor V7; tl 1e jack 2,out-over the subscribers loop,thro'ugh the meter and the subscribersset,back through the jack 2', the

cord conductor 8, the lower vleft impedance 11 and the lead 12 to thenegative terminal ofthe source coil'5, the armature 10., the contactAfter the connection has been completed through the cordicircuit C tothe station Bof the called'subscriber.and when the called sub- *scriberremoveshis receiver from the hook,

the circuit including therelay '9 will be closed;

'The'closure'of this circuit and the resulting energization of the relay9 causes the latter to 'attractciits armature 22 which establishes aconnection with contact 21. The establish- :ment 7 of this connectioncloses 3 the circuit of the relay 18 and causes its energization.

VVhen energized, this-relay attracts its arma- .tures 10 and 10. tobreak their-connection with contacts 11 and 11, respectively, and toestablish their connection with "contacts 16' and 16, respectively;.This brea s the connection of the impedance coils ofv the supply bridgeof the calling. subscriber with the source 3 and connects them to theauxiliary" source 14 throughithe contacts '16 and'16,the leads 1'? and17and the armatures and contacts of re- At this time, the auxiliarysource l4:

line in the same directionias before. At pre determined intervals oftime, for example, 1

the solenoid40 twice, the relay 51 every fifteen seconds, the clock1necl1an-ism53- Z-through' the interrupter 54 closes the circuit At theend of a presecond, the'further rotation of the shaft 58 through theinterrupters 56 and 57 simultaneusly closes the circuits of the relay51and the solenoid 40. The f operation of connects the source 14 fromthecircuit and the operation of solenoid 40 causes the engagee foperates the meter cuit oft-herelay 52'is closed through theinter-"determined are,

ment between the armature 40 and thestop lug 42 to be 'momentarilyreleased. V The causes the generator current and hence the "current ofthe calling subscribers line to be reversed. This reversal which'taikesplace veryrapidly, for, example, in .01 seconds, M of the callingsubscriber.

As soon as tl'iereversal is completed, thecira rupter 55. The operationof tnisrelay causes the source 14 to be'reconnected in the circuit"second, the interrupter 54 in the reverse direction, At the end ofapredetermined-interval of time, ioriexample, one breaks the circuitofthe relay 50 and causes'thegenerator to be disconnected from thecircuit. 7 The current -110w flows from the positive terminal of thesource 14 through theright-hand' contact and armature of the relay 52,the lead 17 the contact 16, the. armature 10", the lower leftiim-cpedancecoil 5, the cord conductor 8, the jack Y 12,- out over the,calling subscribers line,

' back through thejack 2,

the subscribers set,

through the meter and the cord conductor 7 '7, the upper left impedancecoil 5, the armaarmature and contact of therelay 52 tolthe negativeterminal of the source 14. The

meter locatedin the called subscribers loop I is not operated due to thefact that the curse rent therein is not reversed. 1

Although the invention has been described specifically as a currentreversing system, it

should be understood that a system. in which the current isvaried from amaximum to 'zero and rbackagain to a maximum' of the same direction isventlon. V V v V i As shown and described, the generator'is within thescopeof this inconnected on one side of the cord gcireuit only, since,in general, 1t is desirable to of thecordcircuit or on both sides of thecord circuit, if desired. The mechanism shown in the drawing below thedotted line B5 60' may be common to all of the cords'of' it inconnection with a typical relay 51 dis- 5 source and-having ciation ofthe than the relayQ9in si'ich'amannerf that the operation of themeter-willbeginat any desired time duringthe connection. 1

; While this invention has been illustratec cord ci-rcuit used 1in'inanual operation, it is apparent" that it is equally applicabletodia lisysterns. 5 -lVl1at,is'claimed ist j i 1. In combination, a loadcircuit having a sourceof current adapted to'be' connected therein,measuring apparatus insa id. cir-p;

I cuit adapted to beope'rated by' current varia brushes 27 and 28 arerotated through a prefor example, one-halt revo lution, as hithertodescribed, which rotation tions therein, and avo'ltage producinglmeansadaptedto' be connected in sald clrcuit 1n parallel with said source,and havinga plu- 'rality of brushes adapted iodically-through apredetermined arc tovary current variations therein,a'dynainoeelectric j.ma'chine adapted to beconnected in said cir-i cuit in parallel with'said' source, having a plurality of brushes adaptedtobe rotatedperiodically through a predetermined arc to vary the current insaidcircuitwhcnsaid source is disconnected therefrom, and means forreconnecting said sourcein said. circuit aftersaid brushes have beenrotated.- I V In combination, a load circuit having a nectedin saidcircuit in parallel with said P 7 source and having a plurality'ofbrushes tu'ref10, the contact 16, the lead ll, the left I ource' 'ofcurrent connected therein, meter; 1 "mg apparatus responsive to-currentreversals 1n Stud. circuit for measuring the length of time saidcirc'uit is. in use, a generator cona predetermined are to reverse thedirection vof current flow in s'aid circuit when said sourceis'disconnected theretrem and means for reconnecting saidfl'source insaid circuit in its reverse direction-and disconnectingsaid generatortherefrom after said brushes have been rotated.

4. In telephonesystem,subscribersllines,

metering apparatus located in said lines and IBSIJOIlSlVtO currentvariations therein, con- 7 necting circuits for establishing talking con1 nections between said lines,

lt'ential'connectedtoisaid circuits, a dynamo-n V V be'connected in vsaid connecting circuits in paralleliwith said 7 r a plurality ofrotatable- '=brushes, and means'for periodically andsuc-felectricmachine adapted to cessively disconnecting said source from saidcircuits androtatlng said'bru'shes through a predeterminedarcto'varythecurrent'in'said I lines;

'a source of po- 5. 'Ina telep' one system, a calling line and" i meansfor periodically and successivelyimpressing said generator voltage onthe circuit of said calling line in parallel with said battery voltageand in the samedirection theresaid battery voltage; from the I a calledline, gmetering through a predetermined 'arc circuit of said callingmutator brushes through; a 1 predetermined arc to reverse the-polarityor said generator voltage, reimpressing said battery voltage onapparatus located in -i said callingllineand adapted tobe operated bypolarity reversals of the voltage therein,

with, removing line, shifting saidcomthe circuitof said calling line inthe same direction as said generator voltageatter its reversal, andremoving said generator voltage P therefrom.

'6. In a telephone system, a calling-line and a called line, a meterlocated in the circuit between saidlines, a battery connected in the ofsaid calling line and responsive to age, and means parallel with 1direction therewith and brushes through a predetermined arc verse thepolarity of said generator voltage, and for reimpressing sa d batteryvoltage polarity therein, connecting reversals of the voltage talkingconnections circuits for establishing circuit of said calling line, agenerator of substantially thesame voltagejassaid battery and having aplurality of brushes adapted to be rotated through a predetermined arcoperative periodically and successively for impressing said generatorvoltage in the circuit of the 'callingline in said battery andinthe sameremoving saidbatf'or rotating said 1 to ie to reverse the polarity ofsaid generator volttery voltage therefrom,v

on the circuit of said calling linein thesarne direction as saidgenerator voltage after its reversal and removing said generator voltagetheret'rom. I v

,7. In a telephone system, a callingl ne and a called line, ameterlocated in] said calling line and adapted to be operated by polarityreversals of the voltage therein, connecting circuitsv forestablishingtalking connections between said lines,

a battery adapted to supply current to said 5 lines; a second batteryadapted to supply current to said calling line, switching meanscontrolled by the closure 01 the circuit of said called line fordisconnecting said calling line from said first battery and connectingit to said secondbattery, a

dynamo-electric machine adapted to be con- 7 nected parallel with saidsecond battery, a condenser elementin parallel relationship with said"in the circuitotsaid calling ine in dynamo-electric machine, saiddynahio-elec machine including a field magnet having plurality of poles,

an armature, a-commututor, and a pluralityoibru'shes in electricalcontact with opposite sides of said commuta tor and adapted to beshifted through a-piredetermined arc to reverse the polarity of-the hevoltage of said secondbattery therefrom,-

1 machine through a predetermined arc to re i versethe polarity of thevoltage impressed on he circuit of said calling line, reimpressmg,

ting thevbrushes of said dynamo-electric parallel with said secondbattery, removing the voltage or said second'battery onthecircuit ofsaid calling line in the same direction as that of said dynamo-electricmachine after its brushes have been'shi'fted, and removing the voltageof said dynamo-electric machine therelfrom. i Y I 1 8. In a measuringsystem including aload circuit having measuring apparatus respon. siveto voltage variations therein, a source of electrical energy ofsubstantially constant voitage,*aiicl. a second source, of electricalenergy oi variable voltage, the:method vof operating said measuringapparatus which consists in impressing the voltage of both or saidsources inparallel simultaneouslyon said load circuit, removing thevoltage of said first source therefrom, and-gradually vary{ ing thevoltage of said second source to operate said measuring apparatus.

- 9, In a measuring system including a load circuit havinga source ofelectrical energy of substantially constant voltage, measuring apparatusresponsive to polarity reversals of the voltage therein, and a-secondsource of electrical energy the polarity of the voltage "of whichisvariable, the method of operating said measuring apparatu's whichconsists in gradually reversing the polarityof the-voltage of saidsecond source after the voltage of said first source has'been removedfrom said circuit and that of said "secondsoui'ce impressed thereon. o 1a 10, The method of reversing the' =p,olarity of the applied voltage ina work circuit having normallytherein a source of substantially constantvoltage, which consists; in

periodically and successively impressing a variable voltage on said workcircuit in parallel with said source of constant voltage and in thesamedirection therewith, i-emoving saidcoiistant voltage fromsaidcircuit,

gradually reversing the polarity of said vari ablevoltage, reimpressingsaid constant-voltage on said circuit in parallel with said variablevoltage and in the same direction as said variable voltage after itsreversal, and removing said variable voltagefrom said work circuit.

11. The method of reversing the polarity Y of the appliedvoltage in aWork circuit hav I on said circuit same polarity as age and, removing Iingnormally thereina source of substantially constant voltage, whichconsists in impressing ofrsaid variable voltage, 7 said constant voltageon said circuit in its opposlte polarity and removingsald varlablevoltage therefrom.

12. A method of varying the applied voltv age in a Work circuit havingnormally therein a source of substantially constant voltage,

'which consists in removing said constant voltage from said circuitand'simultaneously impressing thereon a variable voltage of the samepolarity as that of said constant voltage, varying said'variablevoltage,and relmpressing-saidconstant voltage on said cir-' cuit andsimultaneouslyremoving said variable voltage therefrom.

In testimony whereof, I have signed my name to vthis specification this19th day of December 1928.

WILLIAMH. EDWARDS.

